In core biopsy, a tissue cylinder of the tumour tissue is removed, for instance with the use of a spring loaded biopsy-needle, and the sample is subsequently examined by means of histology.
In the recent years it has been possible to detect smaller and smaller tumours, for instance through the technical development of screening mammography and ultrasound scanning. It is not unusual to detect tumours which are in the size of just a few millimetres. The tissue surrounding the tumour is often loose fatty tissue, which makes it difficult, when taking a tissue sample, to correctly position and move the needle into the tumour and the problem aggravates if the tumour is hard or fibrous, which is most often the case. Thus, the insertion of the needle into the tumour, if possible, often requires proper training and long time of professional practice and skill.
When using such above-mentioned spring-loaded device for taking a tissue sample, it may sometimes be necessary to take over 10-15 samples in order to obtain a representative sample from the suspected tumour which subsequently can be examined. The spring-loaded device also has the drawback that generally it has to be withdrawn from the target site after each shot in order to reload the device, to make it ready for the next sampling site, and in order to remove the sample from the device. Therefore, this procedure is generally associated with side effects, e.g. extensive local bleeding and pain, and has, due to the positioning problems, the disadvantage that the harvesting area cannot be determined beforehand, which increases the number of needed samples to ensure sample from the right area.
Another problem is also that this procedure might cause significantly increased spreading of tumour cells in the needle tract (seeding), due to the repeated withdrawal of the “contaminated” needle. There is also a risk of spreading when the needle pierces the tumour entirely so that the needle comes out on the opposite side of the tumour.
U.S. Pat. No. 5,538,010 A1 discloses a biopsy needle device of the above mentioned type, including a needle assembly sequentially driven by a spring-loaded drive mechanism. The needle assembly includes an outer cannula through which a stylet is slidably projected to cut and capture a core of the diagnostic tissue.
U.S. Pat. No. 6,485,436 B1 discloses a biopsy needle assembly for removal of multiple biopsy cores from a single penetration. The needle apparatus comprises an elongate assembly of paired sleeves with an open notch in the wall of the outer sleeve for engaging a tissue volume in the bore of that sleeve.
US 2004/0162505 A1 relates to an automated fine needle biopsy device for extracting tissue from the body predominantly in suspected cases of breast cancer. The device causes a fine needle, which is attached to the device, to reciprocate and/or rotate at the same time causing tissue to enter the needle.
U.S. Pat. No. 6,702,761 B1 describes a vibration assisted needle device for use in medical procedures such as needle aspiration biopsies. The needle is reciprocated along its longitudinal axis during operation.
U.S. Pat. No. 4,644,952 relates to a surgical operating instrument that is provided with a mechanism for reciprocation including cams for positive forward and negative rearward movement of a reciprocating shaft without the use of a spring return in one direction.
A possible disadvantage of known fine needle biopsy methods using reciprocal movement is that the reciprocal movement constitutes a considerable strain, especially if the movement is a fast movement.
The inventor has therefore realized that it would be advantageous to provide a movement, in which the fast movement is limited in time and in particular that the movement of the needle is described by a Fourier series and has thus identified a need of an improved arrangement providing good penetration of small and/or hard fibrous tumours.
Moreover, there is a need for an arrangement which provides for accurate guiding of the needle during the insertion and which ensures that the needle directly, at the first insertion of the needle, reaches to a position wherefrom an adequate sample from the tumour may be taken, i.e. an arrangement which makes it possible to make as few penetrations of the surrounding tissue and the tumour as possible.
There is also a need for an arrangement that reduces the experienced discomfort for the patient during the insertion of the needle.
The object of the present invention is thus to provide a core biopsy arrangement and a method for taking a tissue sample from a human or animal tissue, preferably from a tumour or a suspected tumour, which reduces the penetration force needed in order to penetrate the tumour and the surrounding tissue, which provides for accurate positioning and guiding of the needle during the penetration of the surrounding tissue and when taking the sample from the tumour, and which at the same time reduces the discomfort experienced by the patients.
Another object of the present invention is to provide an arrangement which guaranties to collect multiple lesion—specific tissue samples by means of only one needle insertion through the surrounding tissue and biopsy taking entirely within the lesion to be investigated. This considerably reduces the number of times the needle has to penetrate the surrounding tissues to obtain adequate diagnosis.
The object of the present invention is further to provide an arrangement which provides a sufficiently fast forward movement of the needle in order to penetrate the tumour and the surrounding tissue in a sufficient way but which movement at the same time is limited in time.
A yet further object of the inventive arrangement is to lower the risk of cancer spread when taking the sample.